FIG. 1 shows a hitherto known strain transducer which is presently in use in phonograph cartridges. Pads 1 on both ends are linked by a reduced neck 2 at the center, the reduced neck 2 being formed by recesses 3 in the edges of the pads. The cross-sectional area of the reduced neck 2 is smallest at the center, growing larger in the direction toward the pads 1. As the stress is applied in the direction of axis X--X, the stress is concentrated in the reduced neck; a strain thus develops in the reduced neck 2, causing resistance between the two pads 1 to change due to the piezoresistance effect. According to such a structure, the reduced neck 2 has a high sensitivity.
The reduced neck 2, however, has caused a difficulty that variations in the breaking strength thereof are large, that is to say, some of the transducers break easily at the reduced neck. This is the reason why the reliability of the transducer with respect to breaking strength has been low.